First of all the Antimatter Factory... Anyone remembering the Star Trek antiproton gun? Now they have it, but don't worry they're not using it for any nasty purposes. The founding document of CERN prohibits them to use the results for military applications and all results have to be published, so this place really shows the positive side of humanity. It's the antimatter factory so they make antimatter. Antiprotons, positrons and antihydrogen and not only that, they make antiprotonic helium which is basically an ordinary helium atom only one electron around it is replaced by and antiproton... No, the place doesn't look like in Angels and Demons. It's like an industrial estate. Here it comes.
There are really countless cool experiments running in this place here on the Swiss French border, not only the LHC, which is just about to restart this April. There's grand scale innovation going on here. The WWW started here. This alone justifies the existence of this place... Not the internet, but the web as we know it today. The very first website was published by them. A lots of firsts happened here including making antihydrogen for the first time, first PET imaging sensors and the first capacitive touchscreen was made here, too. However, the scientific research is enormous, too. They confirmed loads of details about the standard model and they've found the Higgs boson recently.
I just collated a couple of pictures of the places we visited. I can only recommend to go there when you have the chance.